package com.gem.talkbase.widget;

import com.gem.talkbase.R;

import android.content.Context;  
import android.graphics.Bitmap;  
import android.graphics.BitmapFactory;  
import android.graphics.Canvas;  
import android.graphics.Matrix;  
import android.graphics.Paint;  
import android.graphics.Rect;  
import android.util.AttributeSet;  
import android.view.MotionEvent;  
import android.view.View;  
import android.view.View.OnTouchListener;  
  
public class SlipButton extends View implements OnTouchListener{  
  
    private boolean NowChoose = false;//记录当前按钮是否打开,true为打开,flase为关闭  
    private boolean OnSlip = false;//记录用户是否在滑动的变量  
    private float DownX,NowX;//按下时的x,当前的x,  
    private Rect Btn_On,Btn_Off;//打开和关闭状态下,游标的Rect  
      
    private boolean isChgLsnOn = false;  
    private OnChangedListener ChgLsn;  
      
    private Bitmap bg_on,bg_off,slip_btn;  
      
    public SlipButton(Context context) {  
        super(context);  
        // TODO Auto-generated constructor stub  
        init();  
    }  
  
    public SlipButton(Context context, AttributeSet attrs) {  
        super(context, attrs);  
        // TODO Auto-generated constructor stub  
        init();  
    }  
  
    private void init(){//初始化  
        //载入图片资源  
        bg_on = BitmapFactory.decodeResource(getResources(), R.drawable.slip_bg_on);  
        bg_off = BitmapFactory.decodeResource(getResources(), R.drawable.slip_bg_off);  
        slip_btn = BitmapFactory.decodeResource(getResources(), R.drawable.slip_btn);  
        //获得需要的Rect数据  
        Btn_On = new Rect(0,0,slip_btn.getWidth(),slip_btn.getHeight());  
        Btn_Off = new Rect(  
                bg_off.getWidth()-slip_btn.getWidth(),  
                0,  
                bg_off.getWidth(),  
                slip_btn.getHeight());  
        setOnTouchListener(this);//设置监听器,也可以直接复写OnTouchEvent  
    }  
      
    @Override  
    protected void onDraw(Canvas canvas) {//绘图函数  
        // TODO Auto-generated method stub  
        super.onDraw(canvas);  
        Matrix matrix = new Matrix();  
        Paint paint = new Paint();  
        float x;  
          
        {  
            if(NowX<(bg_on.getWidth()/2))//滑动到前半段与后半段的背景不同,在此做判断  
                canvas.drawBitmap(bg_off,matrix, paint);//画出关闭时的背景  
            else  
                canvas.drawBitmap(bg_on,matrix, paint);//画出打开时的背景  
              
            if(OnSlip)//是否是在滑动状态,  
            {  
                if(NowX >= bg_on.getWidth())//是否划出指定范围,不能让游标跑到外头,必须做这个判断  
                    x = bg_on.getWidth()-slip_btn.getWidth()/2;//减去游标1/2的长度...  
                else  
                    x = NowX - slip_btn.getWidth()/2;  
            }else{//非滑动状态  
                if(NowChoose)//根据现在的开关状态设置画游标的位置  
                    x = Btn_Off.left;  
                else  
                    x = Btn_On.left;  
            }  
        if(x<0)//对游标位置进行异常判断...  
            x = 0;  
        else if(x>bg_on.getWidth()-slip_btn.getWidth())  
            x = bg_on.getWidth()-slip_btn.getWidth();  
        canvas.drawBitmap(slip_btn,x, 0, paint);//画出游标.  
        }  
    }  
  
  
    @Override  
    public boolean onTouch(View v, MotionEvent event) {  
        // TODO Auto-generated method stub  
        switch(event.getAction())//根据动作来执行代码  
        {  
        case MotionEvent.ACTION_MOVE://滑动  
            NowX = event.getX();  
            break;  
        case MotionEvent.ACTION_DOWN://按下  
        if(event.getX()>bg_on.getWidth()||event.getY()>bg_on.getHeight())  
            return false;  
            OnSlip = true;  
            DownX = event.getX();  
            NowX = DownX;  
            break;  
        case MotionEvent.ACTION_UP://松开  
            OnSlip = false;  
            boolean LastChoose = NowChoose;  
            if(event.getX()>=(bg_on.getWidth()/2))  
                NowChoose = true;  
            else  
                NowChoose = false;  
            if(isChgLsnOn&&(LastChoose!=NowChoose))//如果设置了监听器,就调用其方法..  
                ChgLsn.OnChanged(NowChoose);  
            break;  
        default:  
          
        }  
        invalidate();//重画控件  
        return true;  
    }  
      
    public void SetOnChangedListener(OnChangedListener l){//设置监听器,当状态修改的时候  
        isChgLsnOn = true;  
        ChgLsn = l;  
    }  
      
}  